1. Field
One embodiment of the present invention relates to a technique to reduce cross-color/dot interference in a color video picture.
2. Description of the Related Art
In separating a luminance signal (Y) and a chrominance signal (C) from a color television signal, cross-color interference may be caused by leakage of the luminance signal into the chrominance signal and dot interference may be caused by leakage of the chrominance signal into the luminance signal. An apparatus and a method for reducing cross-color/dot interference have been proposed (see Jpn. Pat. Appln. KOKAI Publication No. 2007-67809).
Generally, a circuit to reduce cross-color/dot interference reduces the cross-color/dot interference by taking advantage of the fact that cross-color/dot interference components in consecutive frames have opposite phases with each other and by extracting a cross-color/dot interference component using a filter and averaging extracted cross-color/dot interference components across frames. This is why, in a scene in which a large motion occurs (there is a significant change in images between frames), defects, such as impression of blurring or impression of a residual image, are apt to be generated when an averaging process is performed across the frames. Consequently, in the past, performing a cross-color/dot interference reduction on an image scene in which few motions occur has been a basic operation.
In a conventional cross-color/dot interference reduction circuit, a reduction effect of the cross-color/dot interference has mainly been controlled based on an amount of motion between image frames. However, it is difficult to completely distinguish a moving picture from a difference in cross-color/dot interference components, and this leads to an incompatibility of reducing a cross-color/dot interference and suppressing defects, such as impression of blurring or impression of a residual image. In other words, this causes a trade-off in which the defects, such as the impression of the blurring or the residual image, are more apt to occur depending on an image as the reduction effect of the cross-color/dot interference is more improved, and the cross-color/dot interference becomes more remarkable as the defects, such as the impression of the blurring or the residual image, are more suppressed.